WO2019132290A1

WO2019132290A1 - Battery module having improved cooling structure

Info

Publication number: WO2019132290A1
Application number: PCT/KR2018/015340
Authority: WO
Inventors: 서성원; 강달모; 문정오; 이윤구
Original assignee: 주식회사 엘지화학
Priority date: 2017-12-27
Filing date: 2018-12-05
Publication date: 2019-07-04
Also published as: US11264668B2; HUE062188T2; KR102273195B1; US20200168864A1; ES2946145T3; CN110770965B; KR20190078841A; EP3671946B1; EP3671946A4; PL3671946T3; CN110770965A; JP7045605B2; JP2020523756A; EP3671946A1

Abstract

A battery module, according to one embodiment of the present invention, comprises: a cell stack formed by stacking a plurality of battery cells; a base plate, which receives the cell stack, comprising a module housing composed of a lower housing for covering each of a lower portion, both side portions, front and rear portions, and an upper portion of the cell stack, a pair of side housings, a pair of front and rear housings, and an upper housing, wherein the lower housing completely covers a lower surface of the cell stack; a spacer, which is interposed between the cell stack and the base plate, for partially covering the lower surface of the cell stack to form an empty space between the cell stack and the base plate; a supply pipe which is connected to the spacer to supply a cooling medium to the empty space through the interior of the spacer; and a discharge pipe which is coupled to the spacer to discharge, to the outside, the cooling medium flowing through the empty space and the interior of the spacer.

Description

Battery module with improved cooling structure

The present invention relates to a battery module having an improved cooling structure, and more particularly, to a battery module using an insulating oil for cooling, wherein the insulating oil has a cooling structure that can be in direct contact with the battery cell, To a battery module having the battery module.

This application claims priority from Korean Patent Application No. 10-2017-0180560, filed on December 27, 2017, the contents of which are incorporated herein by reference.

The secondary rechargeable batteries are nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have almost no memory effect compared to nickel- It is very popular because of its low self-discharge rate and high energy density.

These lithium secondary batteries mainly use a lithium-based oxide and a carbonaceous material as a cathode active material and an anode active material, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate each coated with such a positive electrode active material and a negative electrode active material are disposed with a separator interposed therebetween, and an outer casing, that is, a battery case, for sealingly storing the electrode assembly together with the electrolyte solution.

Generally, a lithium secondary battery can be classified into a can type secondary battery in which an electrode assembly is embedded in a metal can, and a pouch type secondary battery in which an electrode assembly is embedded in a pouch of an aluminum laminate sheet, depending on the shape of the casing.

In recent years, secondary batteries are widely used not only in small-sized devices such as portable electronic devices, but also in medium to large-sized devices such as automobiles and electric power storage devices. When used in such a medium to large-sized apparatus, a large number of secondary batteries are electrically connected to increase capacity and output. Particularly, the pouch-type cells are often used because of the advantage that the middle and large-sized apparatuses are easy to be stacked.

However, since the pouch type cell is generally packed in a battery case of a laminate sheet of aluminum and a polymer resin, the mechanical rigidity is not so large. Therefore, when constructing the battery module including a plurality of pouch type cells, a frame is often used in order to protect the secondary battery from external impact, prevent the flow thereof, and facilitate stacking.

The frame can be replaced with various other terms such as a cartridge. In many cases, the frame is formed in the shape of a square plate having an empty central portion. In this case, four side portions surround the outer periphery of the pouch type cell. These frames are used to form a battery module, and the pouch-type cells can be located in an empty space formed when the frames are stacked.

Referring to FIG. 1, a conventional battery module structure is shown. When the plurality of pouch type cells 1 are stacked by using the plurality of frames 2, the conventional battery module structure has a plate-like shape on the outer surface of each pair of pouch type cells 1 By applying the cooling fin 3, the cooling efficiency is increased.

The secondary battery may be used in a high temperature environment such as in the summer, and the secondary battery itself may also generate heat. In this case, when the plurality of secondary batteries are laminated to each other, the temperature of the secondary battery may be further increased. If the temperature is higher than the proper temperature, the performance of the secondary battery may deteriorate, and there is a risk of explosion or ignition in severe cases. Therefore, by applying the cooling fin 3 so as to come into contact with the surface of the pouch type cell 1 when constructing the battery module and bringing the cooling fin 3 into contact with the cooling plate 4 located at the lower portion thereof, A configuration in which the overall temperature rise is prevented is often used.

However, when the battery module is constructed by interposing between the pouch type cells 1 facing the cooling fins 3, which are typically made of a metal material, the surface of the cooling fins 3 and the surface of the learning cell 1 There is a problem that sufficient cooling can not be achieved in a situation where a large amount of heat is generated only by a cooling method that depends on the conductivity of the metal.

Accordingly, there is an urgent need to develop a battery module structure using a cooling method that reduces contact thermal resistance and allows heat to be emitted more efficiently than a simple thermal conduction method.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a battery module to which a cooling structure capable of direct contact between a cooling medium for cooling and a battery cell is applied, So that the cooling can be efficiently performed.

It is to be understood, however, that the technical subject matter of the present invention is not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

According to an aspect of the present invention, there is provided a battery module comprising: a cell stack body formed by stacking a plurality of battery cells; And a module housing configured to house the cell stack body and configured to include a lower housing, a pair of side housings, a pair of front and rear housings, and an upper housing that cover a lower portion, both sides, front and rear, and an upper portion of the cell stacked body Wherein the lower housing comprises: a base plate which covers the entire lower surface of the cell stack body; And a spacer interposed between the cell laminate and the base plate and partially covering the lower surface of the cell laminate to form a void space between the cell laminate and the base plate; A supply pipe connected to the spacer to supply the cooling medium to the empty space through the inside of the spacer; And a discharge pipe connected to the spacer and discharging the cooling medium flowing through the hollow space and the inside of the spacer to the outside; .

An adhesive may be interposed between the cell stack and the spacer so that the cooling medium does not leak between the cell stack and the spacer.

The base plate has a coupling portion formed with coupling grooves on both sides of the base plate. A coupling protrusion protruded downward is provided on the lower end of the side housing. The coupling protrusion is inserted and fixed in the coupling groove, Can be fixed to the plate.

The coupling portion has a protrusion protruding toward the inside of the battery module, and the protrusion is abutted against a battery cell disposed at an outermost position of the cell stack to prevent leakage between the base plate and the cell stack As shown in FIG.

The spacer includes: a first spacer provided on one side of the base plate in the longitudinal direction; A second spacer provided on the other side in the longitudinal direction of the base plate; And a third spacer spaced apart from and spaced apart from the first spacer and the second spacer; . &Lt; / RTI >

The supply pipe may be connected to a first spacer flow path formed through the inside of the first spacer, and the discharge pipe may be connected to a second spacer flow path formed through the inside of the second spacer.

The third spacer may include a third spacer flow path formed so as to penetrate the cooling medium supplied through the first spacer to flow toward the second spacer.

Meanwhile, a battery pack according to an embodiment of the present invention may be realized by connecting a plurality of battery modules according to an embodiment of the present invention, and the automobile according to an embodiment of the present invention may further include: And a battery pack according to an embodiment.

According to an aspect of the present invention, there is provided a battery module to which a cooling structure capable of direct contact between a cooling medium for cooling and a battery cell is applied, thereby efficiently cooling the battery module even when the amount of heat generated by application of the battery module of high capacity and / So that not only the performance of the battery module can be improved but also safety accidents such as ignition / explosion of the battery cell due to a rise in temperature can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further the understanding of the technical idea of the invention. And should not be construed as limiting.

1 is a view showing a cooling structure employed in a conventional battery module.

2 is a completed perspective view showing the appearance of a battery module according to an embodiment of the present invention.

3 is an exploded perspective view of a battery module according to an embodiment of the present invention.

4 is a view showing a state where a cooling medium flows on a base plate constituting a battery module according to an embodiment of the present invention.

5 is a cross-sectional view showing a section taken along the line A-A 'and B-B' in Fig. 2.

Fig. 6 is an enlarged view of the shape of one end of Fig. 5;

7 is a cross-sectional view taken along line C-C 'of FIG. 2;

Fig. 8 is an enlarged view of the shape of one end of Fig. 7;

9 is a view showing an embodiment of a supply pipe and a spacer different from the supply pipe and the spacer shown in Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only some of the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

First, components of the battery module 10 according to an embodiment of the present invention will be schematically described with reference to FIGS. 2 and 3. FIG.

FIG. 2 is a perspective view illustrating a battery module according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of a battery module according to an embodiment of the present invention.

2 and 3, a battery module 10 according to an embodiment of the present invention is implemented in a form including a cell stack 100 and a module housing 20 accommodating the same. The module housing 20 also includes a lower housing 200, a pair of side housings 300, a pair of front and rear housings 400 and an upper housing 500.

The cell stack 100 is obtained by laminating a plurality of battery cells 110. The battery cell 110 used herein is not particularly limited as long as it is a rechargeable secondary battery. For example, a pouch type battery Cells can be applied.

Each of the battery cells 110 may include a pair of electrode leads 111 extending to one side and the other side. The electrode leads 111 include a positive electrode lead and a negative electrode lead. As will be described later, a cooling medium such as insulating oil contacting the lower portion of the cell stack body 100 forms a space between the battery cells 110 constituting the cell stack body 100 between the stacked battery cells 110 It is preferable that it is firmly fixed / sealed by an adhesive or the like so that it can not penetrate through the upper part.

In addition, the electrode leads 111 may be arranged / connected such that the battery cells 110 constituting the cell stack 100 are connected in series, parallel, or a combination of serial and parallel.

The lower housing 200 includes a base plate 210 that covers the entire lower surface of the cell stack 100, a spacer 220 that partially covers the lower surface of the cell stack 100, A supply pipe 230 for supplying a cooling medium such as insulating oil for cooling the battery module 10 and a discharge pipe 240 connected to the spacer 220 for discharging the cooling medium to the outside .

The spacer 220 is interposed between the cell stack 100 and the base plate 210 so as to cover only the lower surface of the cell stack 100 so that the gap between the cell stack 100 and the base plate 210 Thereby forming an empty space. That is, the empty space corresponds to a closed space surrounded by the cell stack 100, the spacer 220, and the base plate 210.

The supply pipe 230 is connected to the spacer 220 from the front of the battery module 10 to supply the cooling medium to the inside of the spacer 220. The cooling medium supplied to the spacer 220 is supplied to the empty space between the cell stack 100 and the base plate 210 through the flow path formed inside the spacer 220.

The discharge pipe 240 is connected to the spacer 220 from the rear of the battery module 10 to discharge the cooling medium flowing through the empty space and the spacer 220 to the outside.

Each of the pair of side housings 300 is a part that covers both sides of the cell stack 100. The pair of side housings 300 is a part of the battery cell 110 constituting the cell stack 100, Facing the wide face of the body 110. Such a pair of side housings 300 can also function to prevent the generation of voids between the battery cells 110 constituting the cell stack 100 by pressing the cell stack 100 on both sides .

The pair of front and rear housings 400 may be embodied as including a bus bar frame 410, an insulating cover 420, and front and rear plates 430, respectively.

The bus bar frame 410 is coupled to the cell stack 100 from the front or rear of the cell stack 100. The electrode leads 111 are inserted into the bus bar frame 410, The bending operation of the electrode lead 111 for the electrical connection between the electrodes is facilitated. That is, the electrode leads 111 are inserted through the insertion slits formed in the bus bar frame 410, and then bent. Thus, the electrode leads 111 are connected to each other by welding or the like.

The insulating cover 420 is inserted / bent into the bus bar frame 410 to prevent contact between the electrode leads 111 which are not in contact with each other among the electrode leads 111 coupled to each other And is coupled onto the bus bar frame 410 to prevent a short due to an external factor.

The front and rear plates 430 are parts to be coupled onto the insulating cover 420 and serve to protect internal components such as the cell stack 100, the bus bar frame 410 and the insulating cover 420.

The upper housing 500 includes a sensing electrode 510 electrically connected to the electrode leads 111 inserted and bent through the bus bar frame 410 disposed above the cell stack 100, And a top plate 520 coupled to an upper portion of the sensing unit 510 to form an outermost layer of the upper housing 500.

Next, a specific cooling structure of the battery module according to an embodiment of the present invention will be described with reference to FIGS. 4 to 8 together with FIG. 2 and FIG.

FIG. 4 is a view showing a state where a cooling medium flows on a base plate constituting a battery module according to an embodiment of the present invention, and FIG. 5 is a sectional view taken along AA 'and B-B' And Fig. 6 is an enlarged view of the shape of one end of Fig. 7 is a cross-sectional view taken along line C-C 'of Fig. 2, and Fig. 8 is an enlarged view of a shape of one end of Fig.

4 to 8, a coupling portion 211 having an engagement groove G formed at a predetermined depth from an upper portion to a lower portion is formed at both side ends of the base plate 210 Respectively. The side housing 300 includes a coupling protrusion 310 protruding downward and a coupling protrusion 310 inserted into the coupling groove G to fix the side housing 300 to the base plate 300. [ 210).

The protruding portion P has a gap between the base plate 210 and the cell stack 100 so that the cooling medium is leaked to the outside of the cell stack 100. The protruding portion P protrudes toward the inside of the battery module, And has a shape extending to abut the battery cell 110 disposed at the outermost portion of the cell stack 100 so as to prevent leakage.

An adhesive is interposed between the cell stack 100 and the spacer 220 so as to prevent leakage of a cooling medium such as an insulating oil between the cell stack 100 and the spacer 220. The cell stack 100 And the spacer 220 as well as a function as a gasket.

Meanwhile, the spacers 220 may include a plurality of unit spacers spaced apart from each other. For example, the spacer 220 may include a first spacer 221 provided at one longitudinal end of the base plate 210, a second spacer (not shown) provided at the other longitudinal end of the base plate 210 222 and a third spacer 223 spaced apart from and spaced apart from the first spacer 221 and the second spacer 222.

However, the number of such unit spacers is not limited to three illustrated in the drawings of the present invention, and it is also possible that more units are provided. That is, it is possible for one or more unit spacers to be spaced apart from each other between the first spacer 221 and the second spacer 222. Hereinafter, for the sake of convenience of description, description will be given taking as an example the case where three unit spacers are provided.

The supply pipe 230 is connected to the first spacer 221 from the front of the battery module 10 to supply the cooling medium for cooling to the battery module 10. [ Similarly, the discharge pipe 240 may be connected to the second spacer 222 from the rear side of the battery module 10 to cool the battery module 10, and to discharge the cooling medium having the increased temperature to the outside.

That is, the supply pipe 230 is connected to a plurality of first spacer flow paths 221a passing through the inside of the first spacer 221 to supply the cooling medium. That is, the supply pipe 230 extends along the extending direction of the first spacer 221 disposed across the width of the base plate 210, that is, the longitudinal direction of the first spacer 221, and the first spacer 221 The first spacer flow path 221a is connected to each of the plurality of first spacer flow paths 221a, and the cooling medium is supplied to all the first spacer flow paths 221a.

The discharge pipe 240 is also connected to a plurality of second spacer flow paths 222a passing through the interior of the second spacer 222 to discharge the cooling medium in the same manner as the supply pipe 230 described above . That is, the discharge tube 240 extends along the extending direction of the second spacer 222 disposed across the width of the base plate 210, that is, the longitudinal direction of the second spacer 222, and the second spacer 222 are individually connected to a plurality of second spacer flow paths 222a that are exposed to the outside of the first and second

spacer flow paths

222, 222 to discharge the cooling medium flowing through all the second spacer flow paths 222a.

The third spacer 223 may be formed in order to allow the cooling medium flowing into the internal space S1 of the battery module 10 to pass through the first spacer 221 to the second spacer 222, And a plurality of third spacer flow paths 223a formed through the inside of the third spacer 223.

The third spacer 223a is exposed to the outside of the third spacer 223 so that the space S1 between the first spacer 221 and the third spacer 223 and the space between the third spacer 223 and the second spacer 223 222 to communicate with the inner space of the third spacer 223.

That is, the cooling medium supplied to the battery module 10 through the supply pipe 230 flows through the supply pipe 230, the first spacer 221, the space S1, the third spacer 223, the space S2, the second spacer 222, and a discharge pipe 240, and is discharged to the outside of the battery module 10.

Next, a battery module according to another embodiment of the present invention will be described with reference to FIG.

The battery module according to another embodiment of the present invention has a slight difference in the connection relationship between the supply pipe 250 and the first spacer 224 and the specific structure of the first spacer 224 as compared with the battery module described above , The other components are substantially the same. Therefore, in describing the battery module according to another embodiment of the present invention, portions different from those of the previous embodiment will be mainly described, and a detailed description of parts overlapping with those of the previous embodiment will be omitted .

9, the battery module according to another embodiment of the present invention may be configured such that the supply pipe 250 and the first spacer 224 are not connected at a plurality of points but connected at one location and connected to the supply pipe 250 The flow path (not shown) of the first spacer 224 has a structure communicating with a plurality of flow paths for discharging the cooling medium.

As described above, the battery module 10 according to the present invention is configured such that the spacers 220 are partially applied between the cell stack 100 and the base plate 210, The cooling medium can be supplied to the empty spaces S1 and S2 formed between the plates 210 so that the cell stack 100 can be in direct contact with the cooling medium, have.

Also, the battery module 10 according to the present invention can be sealed (sealed) in order to solve problems of leakage / leakage which may occur when a liquid cooling medium such as cooling water insulating oil and the battery cell 110 are in direct contact with each other. By applying a reinforced structure, the reliability of the product can be increased.

Also, in the case of a battery pack according to an embodiment of the present invention, which is implemented by electrically connecting a plurality of the battery modules described above, and an automobile having such a battery pack, .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not to be limited to the details thereof and that various changes and modifications will be apparent to those skilled in the art. And various modifications and variations are possible within the scope of the appended claims.

Claims

A cell stack formed by stacking a plurality of battery cells; And

And a module housing configured to house the cell stack body and configured to include a lower housing, a pair of side housings, a pair of front and rear housings, and an upper housing that cover a lower portion, both sides, front and rear, ,

The lower housing comprises:

A base plate which covers the entire lower surface of the cell stack body; And

A spacer interposed between the cell stacked body and the base plate and partially covering the lower surface of the cell stacked body to form a void space between the cell stacked body and the base plate;

A supply pipe connected to the spacer to supply the cooling medium to the empty space through the inside of the spacer; And

A discharge pipe connected to the spacer and discharging the cooling medium flowing through the hollow space and the inside of the spacer to the outside;

.
The method according to claim 1,

And an adhesive is interposed between the cell stack and the spacer so as to prevent leakage of the cooling medium between the cell stack and the spacer.
3. The method of claim 2,

The base plate has a coupling portion formed with coupling grooves on both sides of the base plate. A coupling protrusion protruded downward is provided on the lower end of the side housing. The coupling protrusion is inserted and fixed in the coupling groove, And is fixed to the plate.
The method of claim 3,

The coupling portion has a protrusion protruding toward the inside of the battery module, and the protrusion is abutted against a battery cell disposed at an outermost position of the cell stack to prevent leakage between the base plate and the cell stack Wherein the battery module has an elongated shape.
The method according to claim 1,

The spacer

A first spacer provided on one side in the longitudinal direction of the base plate;

A second spacer provided on the other side in the longitudinal direction of the base plate; And

A third spacer spaced apart from and spaced apart from the first spacer and the second spacer;

The battery module comprising:
6. The method of claim 5,

The supply pipe is connected to a first spacer flow path formed through the inside of the first spacer,

And the discharge pipe is connected to a second spacer flow path formed through the inside of the second spacer.
The method according to claim 6,

Wherein the third spacer comprises:

And a third spacer flow path formed inside the first spacer so that the cooling medium supplied through the first spacer flows into the second spacer.
A battery pack in which a plurality of battery modules according to any one of claims 1 to 7 are connected and implemented.
An automobile having the battery pack according to claim 8.